Manufacture of pulp rovings



July 19, M o SCHUR ET L H,8fi7,599

I MANUFACTURE'OF PULP ROVINGS File d June 27, 1931 Patented July 19,1932 UNITED STATESv PATENT OFFICE MILTON 0. SGHUR AND WILLIAM B.MEGLITZ, OF BERLIN, NEW HAMPSHIRE, AS-

SIGNORS TO BROWN COMPANY, OF BERLIN, NEW HAMPSHIRE, A CORPORATION OFMAINE Application filed June 27,

This invention relates to the manufacture of pulp rovings, its objectbeing to provide a method of and apparatus for producing rovingsdirectly from an aqueous suspension in a satisfactory and economicalman- I usual textile yarns in making twines, fabrics, and analogousproducts.

In accordance with our invention, we progressively deposit from aqueoussuspension ribbons of pulp on a rotary cylinder mould of the type usedin making paper, webs. While the ribbons are wet and still on thecylinder mould, we progressively furl or roll them out into continuousround bodies or rovings, whereupon the rovings may be collect ed and putthrough the desired subsequent manufacturing operations. The cylindermould can be operated in combination with a pulp vat which is designedto deliver an aqueous pulp suspension continuously on one side of themould periphery. The other side of the mould periphery can be engaged bya belt orits equivalent, movin at an angle to the direction of movementof the peripheral surface of the mould, whereby the pulp ribbons carriedon the mould periphery are engaged at their edges by the belt and arefurled or rolled out into round form. While passing from thepulp-depositing station to the furling station, the ribbons may undergodewatering to a quasi-dough-like consistency, at which they are amenableto furling and at the sametime possess suflicient strength to maintaintheir integrity. In order to ensure rovings of uniformly good quality,it is necessary that the furling belt and the mould periphery meet atsubstantially the same rates of speed. This result may be had with-. qutdifliculty when the belt derives its motion through frictional contactwith the cylinder mould. Otherwise, it is necessary to drive the beltpositively and to synchronize its speed through suitable mechanism withthe speed of the cylinder mould.

With the foregoing and other features and MAN UFAOTURE OF PULP ROVINGS1931. Serial No. 547,246.

objects in view, our invention will now be described in conjunction withthe accom-.

panying drawing, wherein Figure 1 represents a section through anapparatus, including a vat, cylinder mould, and roving means embodyingour invention.

F igure' 2 is a front view of the apparatus facing the roving means.

' Figure 3 is an enlarged fragmentary section on the line 33 of Figure1.

Figure 1 represents a vertical section through a modified form of rovingmeans.

Figure 5 is a fragmentary front view of the roving means, with the beltpartly broken away to shoW how it is mounted on a supporting guideroll..

Referring in detail first to Figure 1 of the drawing, 1 represents a vatfor supplying an aqueous pulp suspension at suitable consistency to-arotary cylinder mould 2, one side of whose periphery constantly contactswith the body or pool of pulp suspension maintained at a predetermineddepth in the vat. The cylinder mould is constructed to permit theprogressive deposition thereon in spaced relationship of continuousribbons of pulp from the body of aqueous pulp suspension.-

The particular cylinder mould illustrated is built up of heavy,rugged-parts, including a cylindrical shell 3, whose hollow interior isdivided into several compartments or cylinders, A, B, C and D. Thesechambers are de fined by stationary partitions 4 extending radially froma common core 5, which passes through the enclosure 6 for the shell andserves as a means for supporting the partitions and the closures. Theshell proper makes tight sliding contact with the outer edges of thepartitions 3 and with the closures 6, and may be journaled near its endsfor rotation by suitable means (not shown) in accordance with well-knownpractice. The wall of the shell 3 may, as best shown in F igure 3, be ofsubstantial thickness and have'a series of spaced, peripheral grooves 7,of a width corresponding to the width of the ribbons to be formed. Thesegrooves communicate throughout their length with the interior of theshell by spaced apertures 8 extending inwardly from the bottom of thegrooves through the rest of the shell wall. The wall is coveredexteriorly with wire cloth of, say, 45 or finer mesh, so that the pulpfibers again deposit out ofaqueous suspension as spaced ribbons 10 onthose zones of cloth immediately above the grooves, while the water ofthe suspension passes into the interior of the shell by way of thegrooves and the apertures. As the shell is rotated, it acts to strain orpick up pulp fibers as continuous ribbons from the pool of pulpsuspension next to the peripheral portion progressing over the chamberA. The rate of pick-upf may .be promoted by creating suctio'n in thechamber A through a water-leg or suction pump whose suction terminal isan opening 11 through one of the closures 6 into the chamber A. Thechamber B under the upper side of the shell may be similarly connectedwith.the terminal end 12 of a wet vacuum pump, so that as the shellcarrying the wet pulp ribbons passes thereover, excessivewater isremoved from the ribbons to reduce them to the water content at whichthey can be furled satisfactorily. The small chamber '0 adjacent to thechamber B is under the pressure of air or other suitable gaseous mediumsupplied through the opening 13, and which merely detaches or slightlylifts the suitably dewatered rib bons from the wire cloth justbeforethey enter into the nip formed between the outer side of the shelland the confronting stretch of a roving belt 14 supported and guided ona pair of inclined terminal rolls 15. The belt engages theshell over asubstantial arc of contact, and by virtue of friction is propelled atsubstantially the same rate of speed as the shell periphery, but at anangle to the direction of movement of, the shell periphery. The detachedribbons are thus furled or rolled out into rovings 16, which, afterissuing from the nip may be collected by any suitable mechanism, forinstance, by the pneumatic system described and claimed inapplication'Ser. No. 504,029, filed December 22, 1930, by Milton. 0.Schur. We. have desc r ibed the detachment of the ribbons from the mouldprior to their furling, for the reason that the pillp fibers tend tobecome entangled in and stick to the wire cloth,'with the attendantdanger of being non-uniform-- ly furled or of not being furled at all.If desired, however, only those edges of the ribbons which are to serveas the starters for furling operation may be detached from the wirecloth, for, once furling is initiated by the belt, it tends to gouniformly to completion. Because there is a tendency for the mould topropel the belt vertically and thus to cause it to ride out of positionon the rolls 15, this tendency is preferably neutralized as by ahorizontal roll 17, which rotates in a direction o posite to that of themould by frictional engagement over the requisite arc of contact withthe inoperative stretch of the belting. Either of therolls 15 or the neutralizing roll 17 may be adjustably mounted so as to permit tighteningor loosenin of the rovin belt, as well as to allow contro of the are ccontact between the belt and the cylinder mould. The cylinder mould canbe cleansed of any residual fibers clinging thereing 18 and issuingunder pressure as a shower through the wire cloth. That part of themould interior between the chambers C and D over which the mould p'wsesimmediately after roving need serve no useful function,

but may be closed ofi from the adjacent chambers by an arcuate wall 5 0with which the shell makes nice sliding contact. Rather'than dependlngupon a neutralizing roll to keep the roving belt in place the ravingbelt may be anchored to chains, cables, or straps running in fixedpaths. Thus, as illustrated in Figures 4 and 5, the roving belt may bemade up of a wire cloth 19, of suitable 'mesh, attached to a pluralityof spaced supporting straps 20, .each of which' fits nicely into groovesor tracks 21 formed a suitable source through the chamber openin theterminal rolls 22. The side thrust of .5 the cylinder mould on the wireis thus taken up by the side walls of the tracks and no displacement ofthe roving belt is possible.

In order to secure rovings of consistently uniform diameter, strength,and other characteristics, it is necessary that the pulp rib bons be ofuniformly interfelted texture. This result is fostered by the use of avery dilute or thin pulp suspension and by sup plying the suspension inexcess of the cylinder mould on which the ribbons are deposited. Thepulp vat shown in Figure 1 is'capable of handling an excess of pulpsuspension which is delivered at a fiber content of, say, about 1/50% orless, by way of a supply pipe 23 though the bottom 24 of the vet at apoint somewhat removed from the cylinder mould. The pulp sutslpensionflows under a horizontal plate or be e 25 and flows past the clearanceor throat 26 between the baflle and cylinder mould to build u a pool ofconsiderable depth above the built. The suspension is delivered at sucha rate that it overflows the rear wall 27 of the vat into an overflowcompartment 28, from which it gravitates through a pipe 29' and can berecovered for recirculation through the pulp vat.

It is, of course, possible to change the construction of the variousunits, including the pulp vat, cylinder mould, and roving means, whichenter into the combination hereinbefore described. So far as we areaware, how- 4 and to furl the ribbons directly on the mould intorovings. Not only does such a method make possible the production ofhigh grade rovings, but the apparatus associated with the method iscomparatively simple, compact, and inexpensive. The cylinder mould onwhich the ribbons are formed occupies very little space and yet permitsthe ribbons to under 0 all the steps necessary to the forma tion 0 highgrade rovings, including the step of furling the ribbons directlythereon, where there is little chance for the ribbons to becomeweakened, torn, or snarled. Again, the cylinder mould itself may besturdily built as to resist wear and tear over a long period by theaction of the roving means.

What we claim is:

1. A method which comprises progressively depositing pulp fibers fromaqueous suspension as continuous spaced ribbons on a portion of arotating cylinder mould, and progressively furling the pulp ribbons intorovings on another portion of the mould.

2. method which comprises progressively depositing pulp fibers fromaqueous suspension as continuous spaced ribbons on aportion of arotating cylinder mould, progressively removing water from the wet pulpribbons on another portion of the mould, and progressively furling themon still another portion of the mould.

3. A method which comprises progressively depositing pulp fibers fromaqueous suspension as continuous spaced ribbons on a portion of arotating cylinder mould, progressively removing water from the wet pulpribbons on another portion of the mould, progressively detaching themfrom the mould, and finally progressively furling them on still anotherportion of the mould.

4. The combination with a rotary cylinder mould constructed to permitthe progressive deposition thereon from aqueous suspension of spacedribbons of pul of means for maintaining a constant supp y of pulpsuspension in contact with one portion of the mould, and means forprogressively furling the pulpribbons into rovings on another portion ofthe mould.

5. The combination with a rotary cylinder mould constructed to permitthe progres sive deposition thereon from aqueous suspension of spacedribbons of pulp, of means or maintaining a constant supply of ulpsuspension in contact with one portion 0 the mould and a beltfrictionally engaging another portion of the mould andarranged to bepropelled at an angle to the direction of motion of the mould periphery.

6. The combination with a rotary cylinder mouldconstructedto permit theprogressive deposition thereon from aqueous suspension 5 of spacedribbons of pa] of means for maintaining a constant supp yof pulpsuspension in contact with'one'portion of the mould, a

belt frictionally engaging another portion of the mould and arranged tobe propelled at an angle to the direction-of the mould periphery, andmeans for maintaining the path of said belt fixed.

7. The combination with a rotary cylinder mould constructed to permitthe progressive deposition thereon from aqueous suspension of spacedribbons of pulp, of means for maintaining a constant supply of pulpsuspension in contact with one portion of the mould, an endless belt oneof whose stretches engages another portion of the mould and is arrangedto be frictionally propelled at an angle to the direction of motion ofthe mould periphcry, and a roll-engaging the other stretch of said beltand arranged to be frictionally propelled in a direction opposite to thedirection of motion of the mould periphery.

8. The combination with a rotary cylinder mould constructed to permitthe progressive deposition thereon from aqueous suspension of spacedcontinuous ribbons of pulp and at least two separate chambers withinsaid mould over which said mould successively passes, the first chamberbeing for the ap plication of suction to dewater the pulp ribbonsdeposited on said mould, and the second chamber serving as a reservoirfor a compressed gaseous medium acting to lift the ribbons from themould, of means formaintaining a constant supply of pulp suspensionadjacent to the mould portion overlying said first chamber, and meansfor furling the pulp er serving as a reservoir for a compressed gaseousmedium acting to lift the ribbons,

rom the, mould, of means for maintaining a constant supply of pulpsuspension adjacent said first to the mould portion overlyin chamber,and means for furling t epulp'ribwbons into rovings on the mould portionimmediately beyond said third chamber.

10. The combination with a rotary cylinder mould constructed to permitthe progressive deposition thereon from aqueous suspension of spacedribbons of pulp and a plurality ofseparate chambers within said mouldover which said mould successively passed, the first of said chambersbeing for the application of suction to a portion of said mould to whichpulp suspension may be supplied, the

second chamber being for the application of suction to the ortion ofsaid mould immediately beyond he pulp suspension, the third chamberserving as areservoir for a com- 8 ressed gaseous medium actin to liftthe ribons from the mould, and the ourth chamber being spaced from saidthird chamber and serving as a reservoir for a water supply acting tocleanse the mould from fibers be- 10 fore it again passes over saidfirst chamber,

- or means for maintaining a constant supply of pulp suspension adjacentto the mould portion overlyin said first chamber, and means for furlingt e pulp ribbons into rovings on 5 the mould portion between said thirdand fourth chambers and at which portion said rovings are delivered fromsaid mould.

In testimony whereof we have afiixed our signatures. v

MILTON O. SCHUR.

WILLIAM B. MEGLITZ.

